Formal methods increasingly play an important role in the development
of reliable computer systems, but computer support for formal methods in
general lags well behind the state of the art, and in particular, usually
fails to take account of the situation today, in which most significant
software and hardware systems are developed by large teams, usually
distributed over space and time, using a combination of formal and informal
methods and a variety of tools to attack different facets of the problem,
while struggling with inadequate user interfaces, poor documentation, and
difficult mathematics.

The Tatami project is designing, building and testing web-based tools to
ameloriate these problems, by supporting distributed cooperative work using
multiple logical systems and their integration, by paying careful attention to
user interface design, and by having the tools generate web-based output that
fully documents what was done, is easy to browse, and has links to tutorials
on the underlying mathematics, as well as to informal explanations. The
system is available over the internet, and is well documented and efficient.

Some particular innovations of this project include the following:

Support for first order behavioral logic, via the Kumo proof assistant and
proof website generator, and its underlying BOBJ proof engine. This is a
powerful new logic that can treat states in a natural way, as well as streams
and other infinite data structures, and object oriented features, in addition
to the traditional data structures and functions.

A novel notion of proof that includes not merely formal proof steps, but
also proof explanation and large-grain proof structure, and that allows
informal reasoning to be integrated with fully formal reasoning. This is
supported by an innovative use of a fuzzy logic of confidence levels for proof
parts.

A new protocol that supports distributed cooperative proving over the
internet, keeping track of the relations among multiple versions of tasks,
specifications, proof parts, and explanations.

A novel framework that allows the integration of multiple logical systems
and tools that use them, based on a new theory of "institution morphisms".

A new theory for user interface design, called "algebraic semiotics,"
which holds promise of providing a systematic, scientific approach to this
difficult but crucial aspect of system design.

It has had more than 8,000 hits in the last 3 years (not counting hits
originating at UCSD). Many examples and papers produced by this project are
linked from its homepage, including websites that have been produced by the
Kumo system. The BOBJ proof engine also has a homepage,